Sunspots May Cause Climate Fluctuations

Harvard astrophysicist says recent cooler temps are a result of fewer
sunspots

Published On 4/14/2009 1:28:53 AM

By ERIC W. BAUM

Contributing Writer


Sunspot activity may be a primary factor in climate fluctuations, according
to Willie Soon, a researcher affiliated with the Harvard-Smithsonian Center
for Astrophysics and the Harvard College Observatory, who offered the
hypothesis in an interview with TG Daily, an online news source.

Although many climatologists have cited increases in carbon dioxide as the
primary cause of the temperature increases associated with global warming,
Soon maintained that solar radiation from sunspots also has a great effect.

“The sun is a great driving force to climate change,” Soon said in an
interview with The Crimson yesterday, adding that most observed climate data
could be explained by fluctuations in solar radiation.

Sunspots—pockets of magnetism on the sun’s surface—generate high levels of
energy, which then heat the Earth’s atmosphere.

Soon told TG Daily that the lack of additional energy resulting from a
decrease in sunspots is directly responsible for colder temperatures
experienced in recent years.

He said that, as of last week, there had been sunspots on only 11 days this
year, and there were only 99 days with visible sunspots last year—the
second-lowest total since 1911.

Brian F. Farrell, a Harvard meteorology professor, acknowledged a connection
between sunspot activity and temperatures on the Earth, but cited other
research showing that sunspots only account for an overall temperature
change of a tenth of a degree centigrade.

Farrell did acknowledge that there could have been larger temperature
effects caused by sunspots in the past.

“A strong correlation between the amount of radioactive carbon and
temperature from ice cores has shown that solar activity can affect
temperature,” Farrell said.

He cautioned that the link was “a hypothesis...[that] does not have firm
scientific grounding.”

But Soon said that there have been much greater temperature fluctuations due
to sunspots in the past and that proponents of global warming need to
consider the effects of sunspot activity on global temperatures.


http://www.thecrimson.com/article.aspx?ref=527650